The Companions  did their utmost to convey Islam to the generations succeeding them in the best and most accurate way possible. They sincerely loved it, honestly lived according to it and faithfully preserved it and kept any impurity or irregularity out of it.

Their role in the preservation of Islam was one of utmost importance to its continuation, but they were highly prepared for it by the best teacher and trainer, the Prophet . Thus the studying of this era, especially with respect to the history and authority of the Sunnah, is necessary to all Students of Knowledge.

And since this article will not provide enough details to properly cover the subject, it is recommended that the readers consult the following list of books on the subject:

Studies of Early Hadeeth Literature by M. M. Azami, Sunnah Qabla at-Tadween (the Sunnah before Writing) by Ajaj Al-Khateeb, The Sunnah and its Place in Islam by Mustafa As-Siba'ee, Manhajj an-Naqd fi Uloom Al-Hadeeth (The Methodology of Critique in the Sciences of Hadeeth) by Noor-ud-deen Etr, Al-Hadeeth wal Muhaddithoon (Hadeeth and Hadeeth Narrators) by Muhammad M. Abu Zahou, and Hujjiatus Sunnah (The Authority of the Sunnah) by Houcine Chouat.